Who would have thought that an iPad glitch could ground airline flights? Multiple flights with American Airlines were turned back to the gate Tuesday night, all thanks to a software bug in the pilots' iPads. Now just to be clear, the flights were never in any actual danger.

Back in 2013, American Airlines changed policies that allowed the reduction of 35 pounds of paper manuals out of the cockpit (known as a "flight bag") and replaced them with iPads containing the same information. These are now known as "electronic flight bags," or EFBs.

By federal regulation, flight crews must carry a complete operating manual for the aircraft along with maps, detailed guides for every possible airport along the flight's path and other information. For a modern jet airliner, that operating manual can be immense. Plus, aviation maps are updated every six months and operating manuals even more often. With EFBs, those updates happen electronically and save about 3,000 sheets of paper for every American Airlines pilot each year.

But that's where the problem lies. The entire 737 fleet of American Airlines' planes all experienced a glitch in the electronic flight bag app, forcing "a few dozen" flights back to the gates to update the apps with a Wi-Fi connection before being legal to take off.

“The pilot told us when they were getting ready to take off, the iPad screens went blank, both for the captain and copilot, so they didn’t have the flight plan,” Toni Jacaruso, a passenger on American flight #1654 from Dallas to Austin."

“The pilot came on and said that his first mate’s iPad powered down unexpectedly, and his had too, and that the entire 737 fleet on American had experienced the same behavior,” said passenger Philip McRell, who was also on flight #1654. “It seemed unprecedented and very unfamiliar to the pilots.”

American Airlines representatives confirmed the glitch and stayed in touch with concerned passengers via Twitter.